The invention relates to a casting nozzle which is used to feed molten metal from a tundish into the mold of a continuous casting machine with a travelling mold.
A known casting machine called a caster, contains two metallic belts oppositely positioned which serve as walls of the mold. The belts run over pulleys placed at an entry and an exit side of the mold, which drive, guide and tighten the belts. The belts are intensively cooled externally in order to carry off the heat absorbed from the casting. See E. Herrmann, Handbook on Continuous Casting, pp. 82-85.
Another caster contains two opposite arrangements of metallic blocks which serve as a mold and which circulate in a closed track by means of a drive so that the blocks join tightly over a certain length forming the mold between the two opposite arrangements.
The heat absorbed from the casting is removed by either an internal or an external cooling system. (E. Herrmann, Handbook on Continuous Casting, p. 171-173)
On both casters, the mold is closed on both sides by so-called side dams travelling along with the casting i.e. with the mold walls.
A third caster consists of a so-called casting wheel which has a cavity over its circumference and which is confined by a rim on either side to form three walls of a mold. Accordingly, the cavity corresponds with the cross-section of the casting. The fourth side of the mold consists of a endless metallic belt running tightly over both rims which partly surround the casting wheel. As the casting wheel rotates, the belt moves with it, thus forming a mold travelling along with the casting. See E. Herrmann, Handbook on Continuous Casting, p. 65-77.
On all of these casters, molten metal flows from a tundish by means of a feeding device into the mold. Open as well as closed feeding systems are in use currently, but for high quality casting, a closed feeding system must be used. Molten metal would then be fed from the tundish into the mold by a so-called casting nozzle which extends into the mold, closing the entry side of the mold.
Casting nozzle, hereafter called nozzles, consisting of several assembled parts, are known. Usually such nozzles feature a so-called mouthpiece or tip which is interchangeably mounted at the exit end of the nozzle. See Herrmann, Handbuch des Stranggiessens, p. 60.
It is also known to provide an intermediate part between the mouthpiece and the tundish, with the mouthpiece being connected to the intermediate part by means of a clamping device. See EP-A 0 133 485.
If one considers the width of the casting to be produced, the necessary components for these types of nozzles may have considerable dimensions. Manufacturing costs thus will be very high, requiring expensive investments for their fabrication. While in use, the tundish with the connected nozzle must be precisely positioned in the caster, which is extremely difficult because of the temperatures involved. Such temperatures cause heat dilatations of the support of the tundish, thus requiring complicated and expensive arrangements such as intermediate parts with articulating, spherical joints between tundish and nozzle for compensating unequal dilatations of the different parts. See EP-A 0 133 485.